Advanced MathMediumConstant after expanding and combining two products
Advanced Math practice question
For all values of x, x(x + 3) − 3(x + 3) = x² − k, where k is a constant. What is the value of k?
Answer: 9
x² + 3x − 3x − 9 = x² − 9.
Common wrong answers
- If you answered 3
- 3 copies the number in the factors.
- If you answered 6
- 6 adds 3 and 3.
- If you answered -9
- −9 has the sign wrong for k.
More Advanced Math questions
- Medium
What are the solutions to x² − 5x + 6 = 0? - Medium
The graph of f(x) = (x − 3)² + 4 is a parabola. What are the coordinates of its vertex? - Medium
If x² − 2x − 8 = (x + 2)(x − a), what is the value of a? - Medium
If √(x + 5) = 4, what is the value of x? - Medium
If f(x) = x + 3 and g(x) = 2x, what is f(g(4))? - Medium
What are the solutions to x² + 6x + 8 = 0?
Not affiliated with the College Board. SAT is a trademark of the College Board.